On World Polio Day, despite efforts to eradicate the disease, cases are re-emerging in war-torn Syria.

Public health officials warned this week that Syria may be facing its first polio outbreak in 14 years. Civil unrest in the country has created a perfect storm for the disease to spread: vaccination rates are down to 45% this year from 95% in 2010; at least a third of public hospitals in the country are closed; and as many as 70% of health workers in some areas have fled, the BBC reported on Monday. In South Sudan, authorities have launched an emergency campaign to vaccinate hundreds of thousands of children against the virus by the end of this week, Voice of America reports, after a handful of polio cases were reported among children in September. In May, the disease also began spreading across parts of the Horn of Africa.

These cases could threaten the success of the worldwide campaign to wipe out polio launched in 1988 by the World Health Assembly. Since then, polio cases have plummeted from an estimated 350,000 in more than 125 countries to 223 reported cases in 2012, a drop of more than 99%, according to the World Health Organization. In April 2013, the international community launched a $5.5 billion plan to ramp up child vaccinations in order to eliminate polio by 2018 from the last three countries where the disease is endemic: Afghanistan, Nigeria and Pakistan. If successful, polio will be the second disease wiped out after smallpox.

The program faces challenges, however. In areas where polio has been eradicated, much of the success is due to health workers who provide vaccinations, often under difficult and even life-threatening conditions. In India, where the last case of polio was reported in 2011, the Telegraph on Thursday reported the story of Martha Dodarai, a nurse in the state of Bihar who wakes up at 3 a.m. every day to walk 20 kilometers to a health center in Tilakpur where she vaccinates children. “It takes me three hours to reach Tilakpur,” Dodarai said. “While passing through jungles during my journey, I do get scared at times,” said the 43-year-old, who has been immunizing children at the center for eight years.

In nearby Pakistan, two health workers were killed and another 13 injured on Oct. 8 in a bombing in the country’s Taliban-controlled northwest. It was the latest in a series of attacks targeting vaccination teams since the Taliban announced a ban on polio immunizations in the region in June 2012. Political factors have also hurt the public health campaign; some in Pakistan have been wary of vaccination campaigns after reports that the CIA used a fake vaccination program to collect DNA samples from people living in Osama bin Laden’s compound, according to CNN. The number of polio cases in the country dropped to 58 last year from 173 in 2011, but health officials warn that vaccination bans in the country’s northern regions threaten to derail progress towards ending the disease, not only in Pakistan but also in in neighboring areas, Reuters reported. Already in 2013, there have been 296 reported cases worldwide, including 43 in Pakistan.

Public health officials hope, however, that the strong start to the polio eradication campaign will overcome these obstacles, and they have reason to be optimistic. Of the 296 polio cases recorded this year, only 99 occurred in countries where the disease is endemic (compared to 166 last year) which means strategies to stop the disease in these countries are succeeding, according to the WHO. “The highlight of that progress has been that of the two remaining types of polio virus, type 3 has not been seen anywhere in the world since November last year. That’s very, very important element of progress,” Dr Hamid Jafari, director of the Global Polio Eradication Initiative told allAfrica.com.